$and performs a logical AND operation on an array of two or more
expressions (e.g. expression1, expression2, etc.) and selects the
documents that satisfy all the expressions in the array. The $and
operator uses short-circuit evaluation. If the first expression (e.g.
expression1) evaluates to false, MongoDB will not evaluate the
remaining expressions.

So in your case it does not even make sense to use the AND operator because you also can use an implicit AND, like

db.getCollection('insights').find({author:/jim/i})

To come to your actual problem. I cannot reproduce this issue using native mongodb. In shell: